甲醛对中华绒鳌蟹各期溞状幼体及隐藻的急性毒性

ACUTE TOXICITY OF FORMALIN TO ZOEA OF ERIOCHEIR SINENSIS AND RHODOMONAS BALTICA

通过静水试验法，用甲醛对中华绒螯蟹各期状幼体及隐藻进行急性毒性试验，结果分别为：Z1：24hLC50为41．214mg／L，48hLC50为33．364mg／L，SC为3．34mg／L。Z2：24hLC50为125．497mg／L，48hLC50为54．258mg／L，SC为5．43mg／L。Z3：24hLC50为143．617mg／L，48hLC50为93．817mg／L，SC为9．38mg／L。Z4：24hLC50为200．679mg／L，48hLC50为98．414mg／L，SC为9．84mg／L。甲醛对Z5的毒性状况比较特殊，虽经10次试验仍无规律性。试验表明，30mg／L以下的甲醛，24小时内波海红胞藻全部成活，甲醛对波海红胞藻的6hLC50为：90mg／L，12hLC50为：60．77mg／L，24hLC50为：57．5mg／L。一定浓度的甲醛可杀死苗池水中的赤潮生物，蓄水池中的赤潮生物可用含氯化合物杀灭，以降低赤潮生物对中华绒螯蟹幼体的毒性，提高幼体的变态成活率和育苗产量。

The acute toxicity of formalin to zoea of Eriocheir sinensis and Rhodomonas baltica were determined with static bioassay tests. The experimental results showed that the LC50 values (medium lethal concentration) of formalin for Z1,Z2,Z3,Z4 in 24h and 48h respectively are as follows: Z2: 24h LC50 was 41. 214mg/l, 48h LC50 was 33. 364mg/l,SC was 3. 34mg/l. Z2: 24h LC50 was 125. 497mg/l, 48h LC50 was 54.258mg/l, SC was 5. 43mg/l. Z3: 24h LC50 was 143. 617mg/l, 48h LC50 was 93. 8l7mg/l, SC was 9. 38mg/l. Z4: 24h LC50 was 200. 679mg/l, 48h LC50 was 98. 414mg/l, SC was 9. 84mg/l. The results indicate that the tolerance of Z5 was most sensitive among all of the zoea stages. The toxicity of formalin to Z5 was out of ordinary, but under the normal circumstances, the larvae was safety in 24h, 48h,within 24mg/l of formalin. The LC50 values of formalin for R. baltica in 6h, 12h, 24h were 90mg/l, 60. 77mg/l, 27. 5mg/l respectively. Killing the toxic plankton in the breeding pond with formalin or CuSO4·5H2O could increased the survival rate of larvae. Decreasing the complicated plankton in the storage sea water pond with the chloride can decrease the sea water toxicity of Red-tide to larvae. The water quality management in the breeding of E. sinensis was also proposed.